本文呈現一例罕見由Actinomyces meyeri所致之膿胸合併急性呼吸窘迫症候群（ARDS）個案。病人為54歲男性，臨床表現為發燒、左側胸痛與呼吸困難，初步診斷為肺炎併肋膜積液；發病後一週內快速進展為呼吸衰竭與休克，需接受機械通氣及體外膜氧合（ECMO）支持。在此期間，個案雖一度出現上腹部疼痛主訴，惟經團隊進行臨床胸腹部鑑別評估後，研判該疼痛並非腹部疾病，而是由下肺葉發炎刺激橫膈膜所誘發的轉移性疼痛。後續經胸部影像及肋膜液分析確立膿胸診斷，並於延長培養第12日鑑定出A. meyeri。因其具厭氧且生長緩慢特性，治療由經驗性廣效抗生素調整為高劑量青黴素，並銜接五個月口服抗生素療程。專科護理師於照護過程中執行全面性評估、病情惡化辨識、跨團隊溝通、培養結果追蹤、抗生素管理與出院銜接。經跨領域治療後，病人順利移除 ECMO、脫離呼吸器並出院。本個案凸顯肺部放線菌病診斷挑戰，亦彰顯專科護理師於重症整合照護之實務價值。

This case report describ a rare presentation of empyema caused by Actinomyces meyeri complicated by acute respiratory distress syndrome (ARDS). A 54-year-old man presented with fever, left-sided chest pain, and dyspnea and was initially diagnosed with pneumonia with pneumonia accompanied by pleural effusion. Within one week of symptom onset, his condition rapidly deteriorated, progress-ing to respiratory failure and septic shock, necessitating mechanical ventilation and extracorporeal membrane oxygenation (ECMO) support. During the diagnostic evaluation, the patient developed right upper quadrant abdominal pain. Following a comprehensive clinical assessment and differential diagnosis, the multidisciplinary team determined that the pain represented referred pain caused by di-aphragmatic irritation secondary to right lower lobe inflammation rather than an intra-abdominal dis-order. Subsequent chest imaging and pleural fluid analysis confirmed the diagnosis of empyema, and A. meyeri was identified on day 12 through prolonged culture. Because of the organism’s slow-growing anaerobic characteristics, antimicrobial therapy was de-escalated from empiric broad-spectrum anti-biotics to high-dose penicillin, followed by a five-month course of oral antibiotic therapy. Throughout the patient’s hospitalization, the nurse practitioner played a pivotal role by performing comprehensive clinical assessments, recognizing early clinical deterioration, facilitating interdisciplinary communi-cation, monitoring microbiological culture results, optimizing antimicrobial therapy, and coordinating discharge planning. Following multidisciplinary management, the patient was successfully weaned from ECMO and mechanical ventilation and was discharged in stable condition. This case highlights the diagnostic challenges associated with pulmonary actinomycosis and underscores the essential role of nurse practitioners in the comprehensive management of critically ill patients through integrated, multidisciplinary care.